That's a small function for a Table Gateway model that executes a SQL Join between data of 2 tables and returns the resultset as an array....simply but useful when we work with multiples tables and relationships......It works for ZF2....

zf2_join.php

public function getOrderedByCategory(){
  	$sql = new Sql($this->tableGateway->getAdapter());
		$select = $sql->select('alb_album')->where('alb_album.activo = 1 ORDER BY alb_album.id_categoria ASC');
		$join = $select->join('alb_categoria','alb_album.id_categoria = alb_categoria.id_categoria',array('nombre_categoria'=>'nombre'));
		$statement = $sql->prepareStatementForSqlObject($join);
		$result = $statement->execute();
		$rows = array_values(iterator_to_array($result));
		return $rows;
}